Amyl nitrite (C5H11ONO) is a known vasodilator and is therefore employed to treat heart disease and angina. In addition, amyl nitrite is used as an antidote for cyanide poisoning where it acts as an oxidant to induce the formation of methemogloblin which in turn can attenuate cyanide as cyanomethemoglobin. The alkyl group is generally unreactive and the chemical and biological properties are primarily due to the nitrite (ONO) group.
U.S. Pat. No. 3,106,511 relates to medicament compositions containing amyl nitrite and to their preparation and use. U.S. Pat. No. 4,309,303 relates to a method of stabilizing liquid alkyl nitrites by adding ethyl hydroxyethyl cellulose, calcium silicate and mixtures thereof and mixing to produce solid state compositions and to stabilize compositions thereof. U.S. Patent Publication No. 2003/0149292 relates to the continuous synthesis of alkyl nitrites by reacting an alcohol with an inorganic nitrite in an acidic medium.
Despite previous uses, amyl nitrite's utility as a field antidote treatment is limited by its stability characteristics (presently 2 year storage at 2-8° C. and limited storage at 25° C.). In addition, amyl nitrite is administered by nasal inhalation, which makes it difficult to determine dose level and the amount of amyl nitrite that is delivered (as measured by blood methemogloblin concentration). Additionally, due to unknown dose quantity delivered, no relationships have been established between dose and efficacy or dose and safety.
It is also useful to note that amyl nitrite is a relatively low viscosity and volatile fluid with a boiling point of 97-99° C. As noted, it is typically employed in drug form by inhalation of vapors of the liquid. Accordingly, the relatively high volatility can reduce the efficacy of a dose through evaporation away from the target zone and/or uncontrolled release.